Drivers make their way along 610 near Interstate 10 on Aug. 28. Loop 610 between Interstate 10 and U.S. 59 west of downtown Houston is the most congested segment of highway in the state, according to the newest ranking by the Texas Department of Transportation. Analysts estimate drivers waste 1.18 million hours annually by idling and slowly moving along the highway because of traffic.

Photo: Cody Duty, Houston Chronicle

Drivers make their way along 610 near Interstate 10 on Aug. 28....

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Drivers make their way along 610 near U.S. 59on Aug. 28. Loop 610 between Interstate 10 and U.S. 59 west of downtown Houston is the most congested segment of highway in the state, according to the newest ranking by the Texas Department of Transportation.

Photo: Cody Duty, Houston Chronicle

Drivers make their way along 610 near U.S. 59on Aug. 28. Loop 610...

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Of Houstonâs 10 most congested freeway segments, listed below, the top four also are included among the stateâs most congested list.

Of Houstonâs 10 most congested freeway segments, listed below,...

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Drivers make their way along 610 near I-10, Thursday, Aug. 28, 2014, in Houston. Loop 610 between Interstate 10 and U.S. 59 west of downtown Houston is the most congested segment of highway in the state, according to the newest ranking by the Texas Department of Transportation. Analysts estimate drivers waste 1.18 million hours annually by idling and slowly moving along the highway because of traffic. (Cody Duty / Houston Chronicle)

Houston drivers, especially those west of the central business district, continually waste more time and fuel in clogged traffic than motorists anywhere else in Texas, according to data released Friday.

The data from the Texas A&M Transportation Institute show that Houston's congestion persists stubbornly in the same spots where it has historically been most severe, even as development spreads farther from the urban core.

The worst spot in the state, according to the institute, is along Loop 610 West, between Interstate 10 and U.S. 59. This stretch of Loop 610 through the Uptown area - a bit more than 3 miles long - is, by a wide margin, the freeway segment where Texas drivers waste the most time: 1.18 million hours annually.

Across various segments, all of Loop 610 west of Interstate 45 is in the top 50 statewide in terms of congestion. Also earning this distinction are I-10 from U.S. 59 west to the Grand Parkway and I-45 from the Sam Houston Tollway near Bush Inter­continental Airport to League City.

Two of the state's three most stressful commutes, based on comparing the peak travel time to how long a trip would take in free-flow conditions, are in Houston, along the West Loop between U.S. 59 and I-10, and U.S. 59 east of the central business district.

The findings are based on an annual list of the most congested roads in the state that the Texas Department of Transportation must compile under state law.

The results paint a dire picture of Houston traffic, not surprising to the commuters inching their way along freeways or waiting for crowded park-and-ride buses to take them downtown.

Some progress noted

Judged by how much combined time is wasted, half of Texas' 20 most congested road segments are in Harris County, with nine of those 10 within the Sam Houston Tollway, and most west of the central business district.

Among the top 50 most congested roads, 24 are in the Houston region, with the rest spread around the Dallas, Austin, San Antonio and El Paso areas.

"Everything inside the Loop is congested," said Tim Lomax, a Transportation Institute researcher and co-creator of the list.

The severity of the congestion varies, and many routes have not worsened significantly since last year. Some routes even reported congestion declines, such as U.S. 59 between I-10 and Texas 288, where drivers wasted 666,494 hours, down from 743,006 in 2013.

Easing congestion, however, will involve more than simply adding freeway lanes or expanding public transit, experts say. It will also require providing more traffic information to commuters and giving them more options to delay trips, work from home or ride a bus or train rather than drive.

"It is all of it," said Jack Drake, chairman of Transportation Advocacy Group Houston Region, which argues for transportation investments. "We force ourselves into problems today by not being able to look far enough ahead to make decisions that are in the best interest. Don't preclude options today that we need tomorrow."

Even as jobs and residences have moved farther from the downtown area, leading to traffic problems far and wide, the worst congestion continues to be concentrated among downtown, the Texas Medical Center, Uptown and Greenway Plaza. All of them in some way rely on Loop 610 and U.S. 59 for much of their traffic, Lomax said.

Major centers outside the urban core are - for now - strictly job centers where people commute in during the morning and return to suburban homes in the evening. That differs from more centrally located centers, like Uptown, where people live, work and play.

"I think the interesting part will be when you have Exxon Mobil and the Energy Corridor (expanding beyond just job sites)," Lomax said, referring to the oil giant's new campus under construction in north Harris County. "What happens if they develop in the same way Uptown has?"

Detours for road work

The list indicates the biggest increases in wasted time occurred where Houston drivers are dealing with construction, such as along U.S. 290 and the 290-610 connection, or in spots where drivers seek to avoid that road work, such as I-10.

"We're seeing the same thing in the opposite direction from when the (I-10) was under construction," Lomax said.

I-10 is a case study in the need to keep expectations realistic.

Transportation officials spent $2.8 billion widening the freeway and adding toll lanes in the center in each direction to address crippling traffic congestion. Less than six years later, the freeway remains one of the state's most congested, but it is far improved from its previous condition.

Sara Fishbein, 29, agreed I-10 has improved but said it's still a pain.

"Anywhere around the Loop, it's a mess," Fishbein said. "That's the problem spot. … Until you fix people getting on and off, you're going to have a mess."

Planners acknowledge that Houston isn't fighting for free-flow conditions, but simply seeking tolerable levels of congestion. A city as large as Houston will never have easy peak commutes, but it can hope to contain them, he said.

Consistency, he said, is also important. If someone knows a 4-mile trip is going to take 20 minutes, that becomes routine. But accidents and delays can make trip times swing widely, from a few minutes to 90 minutes. Giving people more current information and opening lanes more quickly after mishaps is vital, Lomax said.

Growth adds to strain

The robust growth in the region makes Houston a destination spot for workers and businesses, but it also strains resources. Some observers have suggested that success is challenged by officials' failure to invest sufficiently in roads and transit, even though borrowing has been inexpensive in recent years.

"All entities have been extremely conservative with their capital spending at a time when construction costs were at historic lows," said D. Wayne Klotz, president of Klotz and Associates, an engineering firm based in Houston. "Interest rates were so low that financing was basically free. While interest rates remain low, construction costs are now rising."

TxDOT officials estimate that they need an additional $5 billion annually for maintenance and construction statewide for the next few years, just to keep congestion from worsening.

A November bond election, if approved by voters, would raise $1.7 billion of that, according to the latest estimates.